Diving weights 101: How to Nail Your Buoyancy Calculations

Nailing your diving weights is as complicated as Scuba diving is breathtaking, right? There is nothing like exploring the shimmering underwater world and its inhabitants. However, it is also a pastime that to be safe requires training, certification and special gear.

One important part of scuba diving is calculating the amount of weight you’ll need to descend and ascend safely during a dive, which can be complicated. An incorrectly weighted dive can be very difficult, but Aquaworld is here to help. Read on to learn everything you need to know about your buoyancy calculations.

The Importance of Diving Weights, Buoyancy and Streamlining

Why is it important that your weighting is right on during a dive? Your air consumption will be improved, you’ll have better control of your body and be able to make smooth descents and ascents, you’ll be able to hold your position during safety checks, and you’ll enjoy your dive more.

If you are not correctly weighted, there will be signs during your dive. For instance, your streamlining will be off. Streamlining allows you to maintain a horizontal position in the water. If you are overweighted, your chest will be high and your legs will be below, and you will have to inflate your BCD (buoyancy control device) to compensate. If you’re underweighted, your legs will be high in the water and your chest will be low and you will have to continuously kick to keep yourself down.

This problem may be fixed by putting more weight on or taking weights off your belt. You can also adjust the location of your weights to see how it affects your balance. Putting weights in trim pockets could be helpful. If your legs are especially buoyant, ankle weights may come in handy. It’s important to remember that correct weighting takes some experimentation.

There’s More Than One Type of Scuba Diving Weight

Image: diving-weights deeperblue.com

All scuba weights are not created equal. The type you use will depend on the kind of suit you are wearing and the depth of your dive. As a general rule, your ideal weighting is calculated by using the equivalent of 1/10 of your weight when using a 5 mm suit in saltwater and a 12-liter tank. This is adjusted depending on the suit you are wearing.

There are three levels of buoyancy; positive buoyancy or floating, negative buoyancy or sinking, and neutral buoyancy, or feeling weightless in the water and not sinking. Neutral buoyancy is the goal. Suits cause buoyancy, which needs to be compensated for. Other things that can affect the amount of weight you need include:

  • Your weight and your body mass index (weight vs. height)
  • Whether you’re in saltwater or freshwater
  • The thickness of your suit
  • The weight of your tank and the air in it, because as the air in the tank is consumed, the tank will become lighter and its buoyancy will become positive, causing you to float

There are various different types of diving weights, including:

1. Lead Block Belts

These are the most common type of diving weights. They are two to three-inch nylon belts and weights are laced through or attached to the belt.

2. Lead Shot Belts

Lead shot belts have a long pouch or pocket that is filled with round lead shots.

3. Pocket Belts

This is a nylon belt with many pockets. Weights are inserted into them.

4. Ankle Weights

These wrap around your ankle and help minimize the stress diving can cause on the upper back.

5. Integrated Weight Systems

These are built into certain BCDs so you don’t need to carry weights in a separate apparatus.

6. V-weights

Used with twin tanks, they feature a triangular lead weight that is positioned between two cylinders.

7. Tail Weights

Basically the same thing as v-weights, they are placed lower between twin tanks.

8. Brace Systems

Brace Systems are a harness belt that may or may not come with a backplate, onto which weights can be attached.

Scuba Weighting Made Easy

Scuba weighting is not an exact science, but here are guidelines to follow:

Women should add 4 to 5 pounds of weight (about 2 kg) if they are diving in saltwater or subtract 4 to 5 pounds (about 2 kg) if diving in freshwater.

Men should add 6 to 7 pounds (about 3 kg) if diving in saltwater or subtract 6 to7 pounds (about 3 kg) if diving in freshwater.

When it comes to exposure suits, the guidelines are as follows:

  • Swimsuit or dive skin, 0.5 – 2 kg add 1 – 4 lb.
  • Thin (3 mm – 1/16 inch) one-piece wet suits, shorties or jumpsuits, add 5% of your body weight
  • Medium thickness 5mm – 3/I6 inch two-piece wet suit, add 10% of your body weight
  • Cold-water 7mm – 1/4-inch two-piece wet suit with hood and boots, add 10% of your body weight, plus 1.5 – 3 kg/3 – 5 lb.
  • Neoprene drysuits, add 10% of your body weight, plus 3 – 5 kg/7 – 10 lb.
  • Shell-style dry suits, add 10% of your body weight, plus 1.5 – 3 kg/3 – 5 lb.
  • Shell-style dry suits, add 10% of your body weight, plus 3 – 7 kg/7 – 14 lb.

Also, a scuba weight calculator (aka diving weight calculator) or a buoyancy calculator are all great tools that can be found online.

The Last Step: Your Buoyancy Check

Now that you know how important it is to be weighted correctly during a dive, the different types of diving weights that are available, and basic guidelines for weighting, it’s time to do a buoyancy check, because a streamlined position means effective air consumption, good control over your ascent and descent control, and overall an effortless dive.

It is not uncommon for a scuba diver to not check their buoyancy, mostly because dive shops rush participants into a dive and don’t provide an opportunity. Try to be the first one in the water and give yourself a chance to check your weighting and adjust your weights if necessary.

A simple buoyancy check consists of:

  1. Initial weight: If you’re not sure where to begin, figure about 10% of your body weight. If you are diving in tropical waters with a thin wetsuit, subtract 4-6 pounds, and if you are diving in cold water with a lot of exposure protection, add 4-6 pounds. Then you can tweak.
  2. Enter the water: Begin at the surface of the water with full diving equipment and an inflated BCD.
  3. Hold a normal breath and deflate your BCD: This is how you will find out if you are properly weighted. If you sink, you are overweighted, and if you pop out of the water, you are underweighted. Ideal weight will keep you floating at about eye-level.
  4. Repeat: Adjust your weight according to the results of the previous step and repeat until you are floating at eye-level.
  5. Compensate for your tank: If you are doing this check with a full tank, add about 4 pounds to compensate for the end-of-dive when the tank will be more buoyant.

Be sure to note the proper weight in your dive log. This will save time when you are in a similar diving environment wearing the same exposure protection.

Mastering diving weights with Aquaworld’s Peak Performance Buoyancy Course

Aquaworld’s Peak Performance Buoyancy course will take your weighting skills to the next level, so you can enjoy scuba diving in Mexico at its best. Good buoyancy is the key to better dives, the difference between a difficult dive and a smooth one, and what differentiates a beginner from an expert. With Aquaworld’s Peak Performance Buoyancy course, you will practice the fundamentals of buoyancy domination during two open water dives in Cancun, which will include learning weight positioning and how to obtain optimal control and balance.

Once your buoyancy skills are perfected, put them to use during one of Aquaworld’s many diving tours at different Cancun dive sites, including the Cancun Underwater Museum and reef, cenote, night, cavern and wreck dives in Cancun, the Riviera Maya and Cozumel.

Are you ready to explore the underwater world to your heart’s content?

? Book one dive and receive 20% off on your second purchase! ?